This a guide on how to use Program, Shutter Priority, Aperture Priority and Manual for landscapes. I did a similar lesson for Portraits here.

Landscape A (1/640, f13)

This shot above was taken of Table Mountain in Cape Town, as a background location for SAX Appeal 2013 magazine (we had to get a permit to shoot next to the highway and the models arrived soon after this shot). I went with Program mode on this sunny day, with a low ISO-200 and a Nikon 18-105mm wideangle lens at 18mm. It was bright enough at 3pm for a short shutter speed (1/640 would be good for sport to freeze motion or be steady handheld) while having a narrow aperture (f/13 is small and lets in little light, but means foreground to background will be in focus which is what I wanted). Click pictures for large versions.

Landscape B (1/250, f/13)

This shot of an economics building at the University of Cape Town was taken at 18mm and ISO-200. If I had shot this in Program Mode, I would have got something like 1/500 and f9. But I accepted a slower shutter speed (one stop lighter, halved to 1/250) and a narrower aperture (one stop darker, to f/13) to get everything in focus. Therefore this shot could have been done in Shutter Priority or Aperture Priority for the same effect. But if I expected to walk into the shade next, shutter priority would be safer, since the Aperture could drop to a wider value of f/4. If I did a shade shot in Aperture Priority at f/13, I would have got something like 1/25 or slower, which is blurry handheld. (To get around that ISO should bes increased manually, or set to Auto, or aperture was made wider such as f/4).

Landscape C (1/250, f11)

Landscape C is similar to the previous shot, with an Aperture of f/11 to get everything in focus. If I really wanted to make sure the roof in the background was in focus too, I might use Aperture Priority to set Aperture to a narrower value of f/16 and lose a stop of light. Shutter speed would halve to 1/125, to gain a stop. Overall brightness would remain the constant, provided I keep the exact same composition.

As you can see in Landscape C, there is a high contrast between the bright sky and sunlit areas compared to the shadows. The camera would have been very sensitive to changing exposure (shutter and aperture) settings if I got a bit more of the sky or shadows in the shot, while I changed my composition. I could have changed to another metering mode or compensated EV (Exposure Value), but still not all the shots would look the same. So this was a good situation for choosing Manual mode. I could then check the histogram or clipped highlights on the camera’s LCD for each shot and I can decide if I need more shadow detail with a brighter exposure, or more sky detail with a darker exposure. I could move shutter speed and aperture in 1/3 of a stop increments for control. For example, shutter could go from 1/250 to 1/200 (brighter) or 1/320 (darker). Aperture could be set from f/11 to f/9 (brighter) or f/13 (darker).

Or I could keep an exposure level I am happy with, but use Manual decide to use a brighter shutter speed and darker aperture, or a darker shutter speed set against a brighter aperture. This would be same result as controlling Aperture as in the first paragraph below the Landscape C picture.

Still confused by all the modes? Read my lesson on the four modes and how to use them. Details on Aperture Scale are in explained on my blog as a lesson here.